Patent GB-1036521-A (GB)
Title: Azidoformates and their use in cross-linking polymers
IPC: C08G63/91
Filed: 1963-01-29
Abstract: Para - phenylazophenyl azidoformate (an orange dyestuff) is prepared by reacting para-phenylazophenyl chloroformate with an alkali azide.ALSO:Novel azidoformates having a boiling point of at least 100 DEG  C at a pressure of 70 mm. of mercury and having the formula R(O.CON3)x, wherein x is an integer of 1 or more and R is an organic radical inert to cross-linking reactions and containing at least one carbon atom per azidoformate radical, are prepared by reacting a chloroformate of the formula R(O.COCl)x with an alkali azide. Exemplified products are noctadecyl, tetramethylene - bis-, pentamethylene - bis-, 1,4 - cyclohexane - dimethyl - bis-, 2 - (1 - para - menthyl - 8 - yloxy) - ethyl, 2-norborn - 5 - enyl - methylene, a ,a 1 - para -xylylenebis-, phenyl, 2,2 - isopropylidene - bis - para, para1 - phenyl-, 2,21 - oxydiethyl - bis-, 2,21oxydipropyl - bis-, 2,21 - ethylenedioxydiethylbis-, 2,21 - thiodiethyl - bis-, 4,41 - thiodibutylbis-, 3 - hydroxy - 4 - benzoylphenyl and 3,5di - tert. - butyl - 4 - hydroxybenzyl azidoformates, the phosphate ester of para-hydroxyphenyl azidoformate and an azidoformate of the formula C(CH2-O-CH2CH(CH3)-O.CON3)4ALSO:Polymeric materials are cross-linked by heating or irradiating them in the presence of azidoformates having a boiling point of at least 100 DEG  C. at a pressure of 70 mm. of mercury and having the formula: (R(O.CON3)x, wherein x is an integer of 1 or more and R is an organic radical inert to cross-linking reactions and containing at least one carbon atom per azidoformate radical. 0.01-20% of the azidoformate may be mechanically mixed with the polymer or added to a polymer solution and heated above its decomposition temperature, e.g. 70-350 DEG  C. Exemplified polymeric materials are ethylene-propylene, styrene-butadiene, ethylacrylate-2-chloroethyl vinyl ether, isobutylene-isoprene, butadiene-acrylonitrile and ethylene-propylene-dicyclopentadiene copolymers, polyethylene, cis-1,4-polyisoprene, polyisobutylene, cis-1,4-polybutadiene, polychloroprene, sulphochlorinated polyethylene, polypropylene, polyvinyl chloride, polystyrene, polyethyl acrylate, polyvinyl acetate, poly-(vinyl methyl ether), poly(ethylene oxide), polymeric 3,3-bis-(chloromethyl)oxetane, vinyl modified polydimethyl siloxane, hydroxyethyl cellulose, nitrocellulose, cellulose acetate butyrate, natural rubber, chlorinated natural rubber, polysulphide rubber, polyurethane rubber (based on toluene diisocyanate and a polyalkylene ether glycol) and mixtures thereof. Also included are alkyd resins formed from pentaerythritol, phthalic anhydride and coconut oil, glycerin, phthalic anhydride and soybean oil, glycerin and phthalic anhydride, soybean oil and castor oil, and a reaction product of diallylidene pentaerythritol and triallyl-pentaerythritol. Exemplified cross - linking agents are tetramethylene-bis(azidoformate), 2,21 - oxydiethyl - bis(azidoformate), 2,21-ethylenedioxydiethyl - bis(azidoformate), 2,21-oxydipropyl - bis(azidoformate), 2,21 - thio-diethyl - bis(azidoformate), pentamethylene-bis(azidoformate), n - octadecyl azidoformate, a ,a 1 - xylylene - bis(azidoformate), C(CH2-O -CH2CH(CH3) - O . CON3)4, 2,2 - isopropylidene - bis(para,para1 - phenylazidoformate), 2 - (1 - para - methyl - 8 - yloxy)-ethyl azidoformate, 1,4 - cyclohexanedimethyl-bis(azidoformate) and para - phenylazophenyl azidoformate.  The last named compound is also a dyestuff and cross-links to form bright orange rubbery materials. Adhesive and coating compositions are formed by dissolving the above polymers and azidoformates in hydrocarbon, ester or alcoholic solvents which may also contain tetra-, di- and dehydro-abietyl alcohols. Such compositions may be deposited as films.  The above cross-linking reactions may also be carried out in the presence of 0.01-1% sulphur and abrasive carbon black fillers, nitrocellulose, toluene, xylene, EtOH, butyl acetate, ethyl acetate, petroleum or polymerized trimethyl dihydroquinoline and phenyl-b -naphthylamine antioxidants.